Catheterization device and associated assembly

Abstract

A catheterization device comprises a catheter, a hollow hypodermic needle longitudinally traversing the catheter, and a pressure detector and indicator attached to the needle at a proximal end thereof for sensing pressures inside a patient upon insertion of a distal tip of the needle into the patient and for qualitatively indicating the sensed pressure. The pressure detector and indicator includes an at least partially transparent housing, a fluid in the housing communicating with a lumen of the needle, and a movable indicator element such as a styrofoam sphere disposed in the fluid in the housing.

What is claimed is: 
     
       1. A catheterization device comprising: a catheter;   a hollow hypodermic needle longitudinally traversing said catheter; and   pressure detection means attached to said needle at a proximal end thereof for sensing pressures inside a patient upon insertion of a distal tip of said needle into the patient and for qualitatively indicating the sensed pressure,   said pressure detection means including: an at least partially transparent housing;   a fluid in said housing operatively communicating with a lumen of said needle; and   a movable float element disposed in said fluid in said housing.     
     
     
       2. The device defined in claim 1 wherein said float is in the form of a sphere. 
     
     
       3. The device defined in claim 2 wherein said sphere is made of styrofoam. 
     
     
       4. The device defined in claim 1 wherein said float is elastically connected to said housing. 
     
     
       5. The device defined in claim 1 wherein said float is connected to said housing via a diaphragm. 
     
     
       6. The device defined in claim 1 wherein said movable float element is one of a plurality of movable indicator elements floating in said fluid. 
     
     
       7. A catheterization method comprising the steps of: providing a catheter and a hollow hypodermic needle longitudinally traversing said catheter;   inserting a distal end of said needle into a patient;   upon insertion of a distal tip of said needle into the patient, automatically sensing pressures at said distal tip;   automatically generating, at a proximal end of said needle, a qualitative indication of the sensed pressure;   upon determining, in response to the qualitiative indication of sensed pressure, that said distal end of said needle has entered an internal organ of a preselected kind, moving said catheter in a distal direction to insert a distal end portion of said catheter into said internal organ; and   withdrawing said needle from the patient upon determining that said distal end of said needle has entered said internal organ.   
     
     
       8. The method defined in claim 7 wherein said step of generating includes the step of moving an indicator element disposed in a fluid filled chamber at said proximal end of said needle. 
     
     
       9. The method defined in claim 8 wherein said indicator element floats in said fluid. 
     
     
       10. The method defined in claim 9 wherein said indicator element is in the form of a sphere. 
     
     
       11. The method defined in claim 8 wherein said step of generating includes the step of reciprocating said indicator element in response to pulsating arterial pressure. 
     
     
       12. The method defined in claim 11, further comprising the steps of (i) removing said needle from the patient upon reciprocation of said indicator element and (ii) placing pressure on the patient at an insertion point of said needle, thereby reducing flow of blood from a punctured artery. 
     
     
       13. The method defined in claim 8 wherein the sensed pressure is negative owing to entry into a lung, said step of generating including the step of moving said indicator element in a distal direction. 
     
     
       14. The method defined in claim 13, further comprising the steps of removing said needle from the patient upon the movement of said indicator element in a distal direction and (ii) reinserting said needle into the patient at a different insertion point. 
     
     
       15. The method defined in claim 7 wherein said step of generating includes the step of moving a diaphragm disposed in a housing at a proximal end of said needle. 
     
     
       16. The method defined in claim 7 wherein said internal organ is a vein and the indication of sensed pressure signals an internal pressure in a venous range, further comprising the step of connecting said catheter to an intravenous fluid source upon moving said catheter in a distal direction to insert said distal end portion of said catheter into said internal organ.